On Wednesday (October 29), fintech company Fiserv's stock price plummeted 44%, marking its worst day ever, after the company lowered its earnings forecast and reshuffled part of its leadership team.

CEO Mike Lyons wrote in a press release, "Our current performance is neither what we want nor what our stakeholders expect."

For the full year, Fiserv now expects adjusted earnings per share of $8.50 to $8.60, down from its previous forecasts of $10.15 and $10.30. Revenue is expected to grow by 3.5% to 4%, compared to a previous forecast of 10%.

Adjusted earnings per share are expected to be $2.04, below LSEG's estimate of $2.64. Revenue is expected to grow by approximately 1% year-over-year to $4.92 billion, below the expected $5.36 billion. Net income rose to $792 million from $564 million in the same period last year.

Along with the earnings announcement, Fiserv also announced a series of executive and board changes.

Fiserv stated that it will transfer its shares from the NYSE to Nasdaq next month, with the ticker symbol "FISV".